Well bit



J. H. HOWARD El" AL WELL BIT April 13, 1937.

Filed April 3, 1935 M w m c w WM a W W H H n h k Patented Apr. 13, 1937 PATENT OFFICE WELL BIT John H. Howard, Huntington Park, and Alfred C. Catland, Alhambra, Califl, assignors to Globe Oil Tools Company, Los Nietos, Oalil'., a corporation of California Application April 3, 1933, Serial No. 664,058

8 Claims.

This invention relates to a well 'drilling tool and relates more particularly to a rotary well drilling bit. It is a general object of the present invention to provide a practical, eflicient and improved bit for use in the rotary method of well drilling.

Another object of the invention is to provide a simplified and improved well drilling bit of the general character or type disclosed in the patent to Lawrence M. Brigham, No. 1,882,545, and thepatent to John H. Howard, No. 1,899,331.

Another object of the invention is to provide a well drilling bit involving a practical, eiiective, and dependable means for removably attaching cutters or cutter units to the shank or body of the bit.

, Another object of the invention is toprovide a well bit that includes cutters rotatably and permanently or non-separably mounted on the projecting. ends of shanks or spindles removably attached to the body of the bit and inclined downwardly and forwardly relative to the direction of rotation of the bit.

Another object of the invention is toprovide a well bit of the character mentioned in which the thrust bearing surfaces on the lower ends of the spindles and in the spindlereceiving openings of the cutters cooperate to seal off the circulation passages where the fluid passes from the spindles or shanks into the cutters.

A further object of the invention is to provide a well bit of the character mentioned including an effective and dependable wedge means for removably attaching the cutter carrying spindles or stems to the body of the bit.

A further object of the invention is to provide a well drilling bit of the character mentioned that is veryeflicient and rapid in operation and that is simple and inexpensive of manufacture.

Other objects and features of the invention will be best and fully understood from the following detailed description of a typical form and application of the invention, throughout which description reference is had to the accompanying drawing, in which:

' Fig. 1 is a front elevation of the ,bit provided by the present invention with a portionbroken away to show one of the cutter units and a part of the body in vertical cross section. Fig. 2 is a side elevation of the bit. Fig. 3 is a transverse detailed sectional view taken as indicated byline 3-3 on Fig. 1, and Fig. 4 is a transverse detailed sectional view of one of the cutters and its mounting, being a view taken as indicated by line 44'on Fig. l.

The well drilling bit provided by the present invention includes, generally, a body I0, cutters II, and means l2 for detachably mounting the cutters on the body.

The shank or body I0 is adapted to be attached to the lower end of an operating string of drill pipe, or the like, and is provided at its upper end with suitable means to facilitate its attachment to the operating string. In the particular case illustrated in the drawing, a tapered screw threaded socket i3 is provided in the upper end of the body ID to receive the pin of a connecting member or the like, of the operating string. The upper portion ll of the body 10 may be of round cross section and may be comparatively long as illustrated in the drawing. In accordance with the invention, two substantially diametrically opposite enlargements 15 are provided on the lower end portion of the body It]. The upper ends iii of the projecting enlargements I5 are inclined downwardly and outwardly, while the lower ends. I! of the enlargements are flat and inclined at substantially 15 relative to a plane normal to the longitudinal axis of the body. The lower ends I! of the two enlargements are pitched or inclined in opposite directions, each being in-' clined upwardly and forwardly relative to the direction of rotation of the drill.

The bit includes two like cutters II for acting on or cutting away the formation at the bottom and sidewalls of the well bore. The bodies l8 of the cutters II are substantially cylindrical and are provided with flat upper ends. Openings or sockets IQ of comparatively large diameter extend into the upper ends of the cutter bodies IQ for the purpose to be subsequently described. A plurality of circumferentially spaced cutting teeth 20 is provided on the body ill of each cutter H. The teeth 20 are provided to ream or cut away the formation at the side walls of the well bore and project beyond the outer sides or surfaces of the body enlargements l5. The teeth 20 may be spiralled longitudinally of the cutters or may be parallel and extend longitudinally of the cutter bodies I8 as illustrated in the drawing. Certain of the reaming teeth 20 have continuations forming lower cutting teeth 2| projecting downwardly from the lower end of the cutter bodies l8 and edges of the teeth 2| are spaced outwardly from the centers or axes of the cutters II. V

The means l2 for removably mounting the cutters II on the body It) includes spindles or stems 23 rotatably carrying the cutters. The upper portions of the stems 23 are tapered upwardly and are carried in correspondingly shaped openings 24 in the enlargements I5 of the body "I. The longitudinal axes of the stems 23 and the openings 24 are inclined upwardly and rearwardly, being substantially normal to the lower ends I! of the body enlargements. In accordance with the invention, the longitudinal axes of the stems 23 lie in planes parallel to a plane including the longitudinal axis of the body Ill, and are inclined upwardly and outwardly in opposite directions at angles of substantially 15 to the vertical. The tapered upper portions of the stems 23 are adapted to accurately fit or seat in the openings 24 and terminate at points spaced below the upper ends of the openings.

The stems 23 project downwardly from the lower ends ll oi. the both! enlargements |5 to rotatably carry the cutters The projecting portions 25 of the stems are cylindrical and extend into the sockets IS in the cutters II. The lower ends of the stems 23 are frusto-conical and the bottom walls of the sockets H! are tapered downwardly and inwardly to cooperate with the ends of the stems. The lower ends of the stems 23 and the bottoms of the sockets l9 cooperate to form thrust bearing surfaces and sealing surfaces as will be hereinafter described. Means is included for permanently or non-separably attaching the cutters H to the lower projecting portions 25 of the stems 23. Opposing or registering annular grooves are provided in the walls of the cutter sockets l9 and in the portions 25 of the stems to form continuous annular spaces 25. A retaining member 21 in the form of a pin is driven into each space 26 through a tangential opening 28 in the cutter to permanently hold the cutter against longitudinal movement on the stem, while allowing free rotation of the cutter relative to the stem. The retaining members 21 extend substantially the entire lengths of the spaces 25 and positively hold the cutters against longitudinal movement on the stems. The upper ends of the cutters may have suitable clearance with the inclined lower ends of the body enlargements i5. The retaining members 21 permanently retain the cutters II on the stems 23 so that the assemblies of the stems and cutters may be replaced as units.

The present invention includes a novel and effective means for removably retaining the cutter carrying stems 23 in the body openings 24. Wedges 30 are arranged in openings 3| in the body enlargement |5 to detachably connect the stems 23 to the body. The wedge carrying openings 3| extend through the body enlargements |5 from one side to the other and partially intersect the openings 24. The openings 3| extend substantially parallel to the inclined lower faces l1 and are of elongate or substantially rectangular cross section. It is a feature of the invention that the wedge carrying openings 3| are pitched or inclined downwardly and outwardly relative to the longitudinal axes of the openings 24 and are related to the openings so that their upper walls intersect the openings 24 while their lower walls do not intersect the openings 24 but have their inner edges at or adjoining the openings 24. The openings 3| are of downwardly and outwardly diminishing cross section, having their lower walls converging toward their upper walls. It has been found practical to form the openings 3| by cutting or milling inwardly into the body enlargement |5 from their exteriors to intersect the openings 23 and to then weld up the outer portions of the openings or slots thus formed. leaving the wedge receiving openings 3| of the desired size and configuration.

Notches 32 are provided in the tapered portions of the stems 23 to register with the wedge receiving openings 3|. After the stems 23 have been positioned in the openings 24 so that their notches 32 are in register with the openings 3|. the wedges 30 may be driven through the openings 3| to removably lock the stems in position. The wedges 30 are shaped to effectively or properly fit the openings 3|. It will be apparent how the tapering wedges driven into the openings 3| will react against the lower walls of the openings 3| so that their upper edges cooperate with the upper walls of the notches 32 to force the stems 23 into tight seating engagement with the walls of the tapered openings 24. The openings 3| are located and related to the stem carrying openings 24 so that the wedges 30 are disposed substantially edgewise to all shearing strains to which they may be subjected. The wedges 30, in being disposed substantially edgewise relative to the shearing forces to which they may be subjected, may be made comparatively thin. The wedges 38 may be formed sufficiently long to project from the opposite ends of the openings 3| and their projecting end portions may be bent over as illustrated in Fig. 3 of the drawing. As the wedges 30 are comparatively thin their projecting end portions may be easily turned or bent over so that they are positively held against displacement or shifting. Drive out openings 40 may be provided in the upper ends of the stem carrying openings 24. Drifts or other suitable tools may be passed through the openings 40 to drive the stems 23 out of the openings 24 after the wedges 30 have been removed. Plugs 4| normally close the drive out openings 48.

The invention provides a simple and effective means for handling the circulation fluid. A central opening 45 is provided in the body III at the lower end of the socket Hi to receive the circulation fluid from the drilling string. Branch openings or passages 46 extend downwardly and outwardly from the lower end of the opening 45 to the upper ends of the stem carrying openings 24. The stems 23 are tubular, having central longitudinal fluid passages 41. In the preferred form of the invention the lower end portions of the fluid passages 41 of the stems are of reduced diameter. Central fluid discharge openings 48 are provided in the lower ends of the cutters II to discharge fluid downwardly. The fluid discharge openings 48 are preferably larger in diameter than the restricted or choked portions of the passages 41. The circulation fluid under pressure discharging from the openings 48 is effecting in flushing the teeth of the cutters II and in maintaining circulation at the bottom of the well bore. A central fluid passage 49 extends downwardly from the lower end of the opening 45 to the lower end of the body |0. The passage 49 discharges from the lower end of the body I0 at a point spaced between two rotatable cutters A flow bean 50 is provided in the lower end of the passage 49 to increase the velocity of the discharging circulation fluid.

It is believed that the operation of the drill acne provided by the present invention will be readily apparent from the foregoing detail description. The drill is attached to the lower end of an operating string of drill pipe, or the like, and is rotated at the bottom of a well bore. The cutters ll rotate independently on the stems 23 during the rotation of the drill. The reaming teeth 20 of the cutters engage and act on the formation at the side walls of the bore to ream the wallsand to cause rotation of the cutters. The lower cutters 2| act on or cut away .the formation at the bottom of the well bore and are continuously flushed by circulation fluid discharged from the openings 48. The outer cutting edges 22 of the cutters 2|, in being curved downwardly and inwardly, engage the side walls of the well bore throughout their lengths so that the cutters are verylong wearing, and are adapted to drill a maximum amount of bore or hole to size. The cutters H in rotating about axes lying in planes parallel to a plane including the central vertical axis of the body In, and in being inclineddownwardly and forwardly relative to the direction of rotation of the drill, have particularly effective cutting engagement with the formation and successively bring the curved cutting edges 22 into cutting and driving engagement with the formation at the side walls of the here. It is to be noted that the forward inclinations of the cutters 'll causes the circulation fluid to bedischarged downwardly and forwardly from the openings 23 as the drill rotates. The retaining members 21, while permitting free rotation of the cutters H, positively prevent displacement of the cutters from the stems 23. The stems 23 carrying the cutters it may be easily and quickly locked in position in the openings 24 by driving the wedges 30 through the openings 3|. The wedges 30 operate to force the stems 23 ings 24 and hold the stems against downward movement in the openings. The wedges 30 have their longest cross sectional dimension extending substantially lengthwise of the openings 241 so that they may be made, comparatively thin.

The comparatively thin wedges 30 are easily driven into the openings 3| and their projectingend portions are readily. bent over to dependably retain the wedges in position. The circulation fluid is handled in a simple and effective manner and thoroughly flushes the teeth of the cutters. The circulation fluid under pressure discharged downwardly from the openings 48 and the flow, bean 50 maintain effective circulation at the bottom of the bore and may aid in destroying or breaking up the formation. Upon the cutters ll becoming worn, the stems 23 may be removed from the openings 24 after driving the wedges 3|] from the openings 3|. If found necessary, a drift, or 0 the like, may be passed through the openings 40 to drive the stems 23 out of the openings 24. New stems 23 carrying renewal cutters l I may replace the removed stems. The drill is simple and inexpensive of manufacture, and is rapid and effective in itsdrilling action.

Having described only a typical form and application of our invention, we do notwish to limit or restrict ourselves to the specific form or application herein set forth, but wish to reserve to ourselves any variations or modifications thatmay appear to those skilled in the art or fall within the scope of the following claims:

Having described our invention, we claim:

1. A well bit of the character described in- 7 eluding, a body having an opening, a removable into their proper seating engagement into openstem in the opening projecting from the body,

the stem, there being an opening in the body substantially transverse of the first mentioned opening and of elongate cross sectional configuration, the second mentioned opening intersecting the first mentioned opening and being disposed so that the line of contact between the stem and wall of the first mentioned opening if extended would pass diagonally through the second mentioned opening, there being a notch in the stem registering with the second mentioned opening, and a removable lock part in the second mentioned opening cooperating with the notch, the lock part beingof the same cross sectional configuration as the second mentioned opening.

2. In a wellbit, a body having a tapered opening, a cutter carrying stem having a tapered portioned opening being disposed so that the plane of contact between the stem and the wall of the tapered opening extends diagonally through the second mentioned opening, there being a recess in the stem registering with the second mentioned opening, and a lock part in the second mentioned opening cooperating with the recess to removably retain the stem in the second mentioned opening.

3. In a well bit, a body having a tapered opening, a cutter carrying stem having a tapered portion fitting said opening, there being an opening in the body of elongate cross section extending transversely of the tapered opening and intersecting the tapered opening, the second mentioned opening being disposed so that the plane of contact between the stem and the wall of the tapered opening extends diagonally through the second mentioned opening, there being a recess in the stem registering with the second mentioned opening, and a lock part in the second mentioned opening cooperating with the recess to removably retain the stem in the second mentioned opening, the end portions of the lock part projecting from the body and being bent over.

4. In a well bit, a body having a tapered opening, a cutter carrying stem having a tapered portion fitting said opening, there being an opening in the body of elongate cross section extending transversely of the tapered opening and intersecting the tapered opening, the second mentioned opening being disposed so that the plane of contact between the stem and the wall of the tapered opening extends diagonally through the second mentioned opening, the upper and lower walls of the second mentioned opening being longitudinally convergent, there being a recess in the stem registering with the second mentioned opening, and a lock part fitting the second mentioned opening and cooperating with the recess to retain the stem in the opening.

5. In a. Well bit, a body having a tapered opening,. a cutter carrying stem having a tapered portion fitting said opening, there being an opening in the body of elongate cross section extending transversely of the tapered opening and intersecting the tapered opening, the second mentioned opening being disposed so that the plane of contact between the stem and the wall of the tapered opening extends diagonally through the second mentioned opening, the upper and lower walls of the second mentioned opening being longitudinally convergent, there being a recess in the stem registering with the second mentioned opening, and a lock part fitting the second mentioned opening and coop- 5 erating with the recess to retain the stem in the opening, and to urge the stem into the tapered opening, the small end portion of the lock part projecting from the body and being bent over.

6. In a well bit, a body having a tapered openlu ing, a cutter carrying stem having a tapered portion fitting said opening, there being an opening in the body of elongate cross section extending transversely of the tapered opening and intersecting the tapered opening, the second mentioned opening being disposed so that the plane of contact between the stem and the wall of the tapered opening extends diagonally through the second mentioned opening and so that its greatest cross sectional dimension lies in a plane inclined upwardly and inwardly relative to the longitudinal axis of the tapered opening, there being a recess in the stem registering with the second mentioned opening, a wedge closely fitting the second mentioned opening cooperating with the recess to retain the stem in the tapered opening. and means holding the wedge against longitudinal movement.

'7. In a well bit, a body having a tapered openin a cutter carrying stem having a tapered portion fitting said opening, there being a polygonal opening in the body of elongate cross section extending transversely of the tapered opening and intersecting the tapered opening, the second mentioned opening being disposed so that the plane of contact between the stem and the wall of the tapered opening extends diagonally through the second mentioned opening, and so that its greatest cross sectional dimension lies in a plane inclined upwardly and inwardly relative to the longitudinal axis of the tapered opening, there being a recess in the stem registering with the second mentioned opening, and a wedge closely fitting the second mentioned opening cooperating with the recess to retain the stem in the tapered opening, the wedge having a projectin'g portion at its small end bent over.

8. A well bit including, a body having openings in its lower end, stems removably retained in the openings and projecting from the body, cutters having sockets rotatably receiving the lower end portions of the stems and having walls extending across the lower ends of the stems, means connecting the cutters with the stems for rotation, there being fluid passages in the body extending to the upper ends of said openings, there being openings in the said walls of the cutters for discharging the fluid, the stems being tubular to pass fluid from said fluid passages to the openings in the cutters, the lower ends of the stems cooperating with the bottoms of the sockets to prevent the leakage of fluid and to act as bearing surfaces, there being a fluid passage in the body discharging from the body at a point between the cutters, and wedge means retaining the stems in the first mentioned openings in close contact with the walls thereof.

JOHN H. HOWARD. ALFRED C. CA'I'LAND. 

